Second malignant neoplasms in survivors of Wilms' tumor: a report from the National Wilms' Tumor Study.

Between October 1969 and December 1982, 2,438 patients were enrolled in the National Wilms' Tumor Study and contributed 14,381 person-years of observation to a follow-up study for the occurrence of second malignant neoplasms (SMNs). Fifteen SMNs were observed, whereas 1.77 would have been expected from U.S. incidence rates for 1973-1977 [relative risk = 8.5; 95% confidence interval (CI) = 4.7, 14.0]. Ten years after the Wilms' tumor diagnosis, the cumulative risk of SMN was 1%. The relative risks compared to standard rates were 12/1.11 = 10.8 (95% CI = 5.6, 18.9) for those who received radiation as part of the initial course of treatment and 3/0.60 = 5.0 (95% CI = 1.0, 14.6) for those who did not, but this difference was not statistically significant. Preliminary data suggest that substantial numbers of SMNs occur as patients are followed greater than 10 years from diagnosis.

Acute toxicities associated with radiation in the second National Wilms' Tumor Study.

Twenty-three of 303 patients (7.6%) entered into National Wilms' Tumor Study Number 2 (NWTS-2) with groups II, III, and IV disease experienced 26 toxic events thought to be related to radiotherapy (RT). The randomization between vincristine (VCR) plus dactinomycin (AMD) and the same two drugs plus doxorubicin (ADR) had a minimal effect on RT toxicity. Five (1.6%) fatalities were recorded and the surviving 18 patients recovered without discernible residua. Sixteen patients had hepatic, four had pulmonary, and three had cardiac toxicity. Hepatic toxicity was significantly more common when the right side of the abdomen or the whole abdomen was irradiated than when the left side was treated (P = .01). We conclude that acute RT-related toxicity in NWTS-2 was very similar to that in NWTS-1, in which 26 (7.2%) of 359 randomized patients developed RT-related toxicity and three died. This acceptable rate was maintained despite more intensive chemotherapy (CT) in NWTS-2.

Outcomes in low-risk babies treated with half-dose chemotherapy according to the Third National Wilms' Tumor Study.

PURPOSE: To determine whether the 50% dose reduction of all chemotherapeutic agents recommended for babies (less than or equal to 12 months of age) by the Third National Wilms' Tumor Study (NWTS-3) produced acceptable toxicity without sacrificing any survival benefit. MATERIALS AND METHODS: The 365 babies enrolled in NWTS-3 had tumors of varying histologies and stages. The present analysis was restricted to the 256 infants who had tumors of favorable histology, were free of metastasis at diagnosis, and received treatment according to NWTS-3 guidelines. RESULTS: Despite the recommended attenuation of drug doses observed in 75% of the chemotherapy courses received, outcomes for these babies were comparable to those obtained in older children given full doses of chemotherapy. Four-year survival rates for 256 babies with stages I (n = 199), II (n = 38), and III (n = 19) favorable-histology tumors were 96%, 95%, and 90%, respectively. The figures for 498 stage I, 342 stage II, and 373 stage III older children with favorable-histology lesions were 92%, 94%, and 91% in that order. There were no deaths from hematologic toxicity or infection among babies who received half-dose chemotherapy. The death rates for their older NWTS-3 counterparts was 1%. CONCLUSION: Less aggressive therapies advocated for babies in NWTS-3 provide acceptable levels of morbidity without compromising the excellent results previously reported for low-risk patients of all ages.

Comparison of high-dose and low-dose radiation with and without chemotherapy for children with Hodgkin's disease: an analysis of the experience at the Children's Hospital of Philadelphia and the Hospital of the University of Pennsylvania.

PURPOSE: In an effort to minimize complications related to high-dose radiotherapy (RT), children with Hodgkin's disease are often treated with low-dose RT (less than 25 Gy) plus chemotherapy. We performed a retrospective study comparing the results in these children with those from children treated with higher doses of RT (30 to 40 Gy) with or without chemotherapy. PATIENTS AND METHODS: From 1970 to 1988, 121 patients younger than 18 years of age with newly diagnosed Hodgkin's disease were treated at the Children's Hospital of Philadelphia (CHOP) and the Hospital of the University of Pennsylvania (HUP). Before 1977, most children underwent laparotomy and received high-dose RT with or without chemotherapy. Since then, high-dose RT alone has been reserved for pathologic stage IA and IIA postpubertal children without large mediastinal masses. In general, most postpubertal children with stage IIB through IVB disease or large mediastinal masses and all prepubertal children have received low-dose RT plus chemotherapy without laparotomy. RESULTS: The 10-year actuarial survival for all children was 86%, and the event-free survival (EFS) was 67% (median follow-up, 6.6 years). For 58 children treated with low-dose RT plus chemotherapy, 10-year survival and EFS (median follow-up, 6.8 years) were 88% and 67%, respectively. The corresponding figures for 10-year survival and EFS in 48 children treated with high-dose RT with or without chemotherapy were 88% and 66%, respectively. In children receiving combined modality therapy, the in-field failure rate was 7% for sites given between 17.5 and 22.5 Gy and 2% for sites given more than 32.5 Gy. In children receiving RT alone, the failure rate was 5% for sites given more than 32.5 Gy. CONCLUSION: We conclude that low-dose RT plus chemotherapy has yielded results comparable to those with higher doses of RT with or without chemotherapy.

Successful management of low-stage neuroblastoma without adjuvant therapies: a comparison of two decades, 1972 through 1981 and 1982 through 1992, in a single institution.

PURPOSE: A review was undertaken of 119 children seen at the Children's Hospital of Philadelphia between 1972 and 1992 to assess the impact of adjuvant therapies for patients with low-stage neuroblastoma (NBL). PATIENTS AND METHODS: Twenty-one of 119 International Neuroblastoma Staging System (INSS) stage 1, 2a, 2b, and 4s patients seen received initial adjuvant treatment postoperatively and 98 did not. The patients were further subdivided according to decade, age, presence of residual disease, and lymph node status. Outcomes were then compared. RESULTS: The event-free survival (EFS) rate for those who received adjuvant therapy was 52% versus 86% for those who did not. The 5-year survival rate was 68% and 94%, respectively. Age (< or > 12 months), extent of residual disease, and status of lymph nodes did not influence survival. Over the two decades, the reasons for selecting treatment changed as new and powerful additional prognostic factors were identified; 71% of patients received no adjuvant treatment in the first decade, compared with 90% in the second. EFS rates for untreated patients by decade were 79% and 89%, and 5-year survival rates were 85% and 98%, respectively. CONCLUSION: It is possible to define most low-stage NBL as favorable-even in patients with positive lymph nodes and gross residual disease-and to omit initial adjuvant treatments successfully.

Treatment outcomes in patients less than 2 years of age with small, stage I, favorable-histology Wilms' tumors: a report from the National Wilms' Tumor Study.

PURPOSE: Retrospective analyses were performed to determine the effect of tumor weight and therapy modifications on outcome in patients less than 2 years of age with stage I favorable-histology Wilms' tumors. PATIENTS AND METHODS: The 4-year relapse-free and overall survival percentages for patients randomized to different treatment regimens in National Wilms' Tumor Studies (NWTS)-1, -2, and -3 were calculated and compared. RESULTS: The 4-year relapse-free survival percentages of patients whose specimen weight was less than 550 g were found to be 89.1% on NWTS-1, 96.0% on NWTS-2, and 93.2% on NWTS-3. There was no evidence that the relapse-free survival of these patients had improved over time (P value for trend = .99). The 4-year relapse-free survival percentage for similar age and stage patients whose specimen weight was 550 g or greater was significantly poorer than that of patients with smaller tumors (P = .02). CONCLUSION: Changes in the NWTS treatment regimens over a period of more than 20 years have not improved on the excellent prognosis of patients who are less than 2 years of age at diagnosis and who have a stage I, favorable-histology Wilms' tumor with specimen weight less than 550 g. These data could be used as the basis for a future trial in which a subgroup of such patients is treated with nephrectomy only.

Prognostic factors for children with recurrent Wilms' tumor: results from the Second and Third National Wilms' Tumor Study.

The characteristics of 367 stage I-IV National Wilms' Tumor Study (NWTS) children who relapsed after initial treatment for unilateral disease in the second and third NWTS trials (NWTS-2 and -3) were analyzed to identify features predictive of survival. Although modifications in initial therapy resulted in a lower rate of first relapse in these two studies compared with NWTS-1, all previously identified prognostic factors after relapse remained statistically significant predictors of survival. Tumor histology, length of initial remission, initial therapy with two v three drugs, and site of relapse each were independently predictive of postrelapse survival. The 3-year postrelapse survival for all 367 patients was 30% +/- 3%; however, subgroups classified by these prognostic factors were identified that had 3-year postrelapse survival rates of greater than 40%. These subgroups included patients who had tumors of favorable histology (FH) that recurred (1) only in the lungs, (2) in the abdomen when radiotherapy (RT) was not initially given, or (3) that were originally stage I, (4) that were originally treated with only two drugs, or (5) that recurred 12 months or more after diagnosis. These results were achieved with the use of standard treatments, ie, surgery, RT, and chemotherapy using dactinomycin (AMD), vincristine (VCR), and Adriamycin [( ADR] doxorubicin; Adria Laboratories, Columbus, OH). It is suggested that patients in these groups might be managed with aggressive use of conventional therapies until newer chemotherapeutic agents and drug combinations are shown to be more effective. Patients with adverse prognostic features at relapse have a poor survival expectancy with standard measures. Salvage attempts for these patients are better based on experimental approaches.

Abdominal relapses in irradiated second National Wilms' Tumor Study patients.

Ten of 259 (3.8%) irradiated patients with group 2 and 3 tumors in the second National Wilms' Tumor Study experienced initial clinical relapse either in the operative site or elsewhere in the abdomen, excluding the liver and opposite kidney. Analysis of factors associated with abdominal recurrences has shown the independent significance of unfavorable histology, field size of the radiotherapy portals, and a postoperative delay of ten or more days before starting irradiation.

Anaplastic Wilms' tumor: clinical and pathologic studies.

A review of almost 1,200 children participating in the first and second National Wilms' Tumor Study (NWTS-1 and -2) has demonstrated a number of significant differences in the clinical presentation and response to therapy of anaplastic and nonanaplastic Wilms' tumor. Compared to their counterparts, children with anaplastic Wilms' tumor were generally one to two years older at diagnosis, more were non-white, and more had lymph node metastases at diagnosis. Consistent with previous studies, children with anaplastic Wilms' tumor survived for a significantly shorter time than those with non-anaplastic Wilms' tumor. A hopeful outlook, however, was suggested by the NWTS-2 experience since the more aggressive chemotherapies used in this study appear to have substantially improved the survival of patients with diffusely anaplastic tumors. Also, the survival of NWTS-2 patients with anaplastic Wilms' tumor was determined in part by clinicopathologic stage. It may be possible therefore to refine therapy according to stage so as to provide children with localized disease a chance for cure with fewer untoward treatment-related sequelae.

The treatment of Wilms' tumor patients with pulmonary metastases detected only with computed tomography: a report from the National Wilms' Tumor Study.

To evaluate the prognosis of patients with Wilms' tumor who have pulmonary densities identified on a computed tomographic (CT) scan of the chest, but have a negative plain chest radiograph, we reviewed the treatments and outcome of 32 patients randomized or followed on National Wilms' Tumor Study (NWTS)-3. The 4-year event-free and overall survival percentages of 18 of these patients who had a favorable histology tumor and were treated as stage IV tumors with three or four drugs plus whole-lung irradiation were 88.1% and 94.0%, respectively. The 4-year event-free and overall survival percentages for nine favorable histology patients treated less aggressively based on the extent of locoregional disease with two or three drugs and without whole-lung irradiation were 88.9% and 88.0%, respectively. There were no statistically significant differences in the 4-year event-free or overall survival percentages between the two groups. The current data do not demonstrate improved survival for favorable histology patients treated with whole-lung irradiation for pulmonary metastases identified only on chest CT scan. However, due to the small number of patients included, no statistically valid conclusions regarding the roles of Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH) and/or whole-lung irradiation in the treatment of these patients can be drawn from the present analysis. Additional patients need to be systematically studied to determine if these preliminary observations can be confirmed.

Severe hepatic toxicity after treatment with vincristine and dactinomycin using single-dose or divided-dose schedules: a report from the National Wilms' Tumor Study.

To evaluate the effect of dactinomycin (AMD) dose and schedule on the frequency of severe hepatic toxicity in unirradiated National Wilms' Tumor Study-4 (NWTS-4) patients, we reviewed the records of 154 children randomized to single-dose AMD and 176 children randomized to divided-dose AMD administration. All the children also received vincristine in identical dose schedules for the first 10 weeks. The frequency of severe hepatic toxicity encountered in the early weeks of therapy was 14.3% (five of 35) among patients treated with 60 micrograms/kg of AMD, 3.7% (four of 108) among patients given 45 micrograms/kg, and 2.8% (five of 176) among patients treated with 15 micrograms/kg per dose times five doses (P = .025). The data suggest an increased frequency of severe hepatic toxicity with the higher, single-dose schedule of administration. However, the frequency of severe hepatic toxicity among the patients in the two remaining groups is markedly higher than the 0.4% observed among similar unirradiated patients in NWTS-3. The relationship of this toxicity to factors such as anesthetic agents, blood transfusions, intercurrent viral infection, or other presently unrecognized causes can be further evaluated only with a detailed investigation such as a case-control study.

Second malignant neoplasms following treatment for Wilm's tumor: a report from the National Wilms' Tumor Study Group.

PURPOSE: The study was undertaken to determine the incidence of second malignant neoplasms (SMNs) in patients treated for Wilms' tumor and demonstrate how the incidence varied with the initial treatment protocol. PATIENTS AND METHODS: Between October 1969 and December 1991, 5,278 assessable patients were enrolled onto the National Wilms' Tumor Study (NWTS) and by the end of 1993 had contributed 39,461 person-years to a follow-up study. Expected numbers of second cancers were calculated by applying national incidence rates to person-years classified by age, sex, and calendar year. RESULTS: Forty-three SMNs were observed, whereas only 5.1 were expected (standardized incidence ratio [SIR], 8.4; 95% confidence interval [CI], 6.1 to 11.4). Fifteen years after the Wilms' tumor diagnosis, the cumulative incidence of a SMN was 1.6% and increasing steadily. Abdominal irradiation received as part of the initial therapy increased the risk of a SMN (SIR, 1.43/10 Gy; 95% CI, 1.13 to 1.81). Doxorubicin potentiated the radiation effect. Among 234 patients who received doxorubicin and greater than 35 Gy of abdominal radiation, eight SMNs were observed, whereas only 0.22 were expected (SIR, 36; 95% CI, 16 to 72). Treatment for relapse further increased the SMN risk by a factor of 4 to 5. CONCLUSION: These results demonstrate the importance of current efforts to limit the use of intensive chemotherapy and radiation therapy, which are now applied only to patients with the most aggressive disease. Continuing close surveillance of the great majority of Wilms' tumor patients who become long-term survivors is essential for early diagnosis of SMNs and other late sequelae of therapy.

Effects of radiation on ovarian function in long-term survivors of childhood acute lymphoblastic leukemia: a report from the Childrens Cancer Study Group.

The Childrens Cancer Study Group has assessed serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and pubertal development in 97 long-term female survivors of childhood acute lymphoblastic leukemia (ALL). All patients received identical induction and maintenance therapy with either 18 or 24 Gy of radiation therapy (RT) to one of the following fields: cranial, craniospinal, or craniospinal plus 12 Gy abdominal RT including the ovaries. Thirty-six percent (35 patients) were found to have above normal levels of FSH and/or LH. The percentages of elevated values for RT fields were 93% for craniospinal plus abdominal RT, 49% for craniospinal RT, and 9% for cranial RT (P less than .001). A dose-response relationship was observed between 18 Gy and 24 Gy in females receiving only craniospinal RT (P = .01). Craniospinal plus abdominal RT and abnormal FSH/LH levels were significantly associated with lack of pubertal development and delayed onset of menses. Duration of maintenance chemotherapy was not associated with abnormal gonadotropin levels or the development of secondary sexual characteristics. Additional follow-up of this cohort is needed to establish the ultimate pubertal development and fertility of these patients.

Long-term evaluation of a CNS prophylaxis trial--treatment comparisons and outcome after CNS relapse in childhood ALL: a report from the Childrens Cancer Study Group.

The current status of children with acute lymphoblastic leukemia (ALL) who had developed CNS disease while being treated on protocol CCG-101 was investigated. Seven hundred thirty-six eligible patients were entered into the study between June 1972 and July 1974. All children who were greater than 18 months of age were eligible for randomization to a CNS prophylaxis trial for which one regimen gave only a short course of intrathecal methotrexate (IT MTX) as prophylaxis. All other regimens included radiation therapy as prophylaxis. Current follow-up (median, greater than 10 years) shows no significant difference by standard life-table analysis for ultimate survival, although a substantial excess of CNS episodes occurred on the IT MTX regimen. Of the 675 patients who completed induction therapy and achieved remission in the study, 100 (14.8%) developed CNS disease as the first evidence of relapse. Fifty-five of these 100 had no subsequent CNS episodes. Only 17 of these 55 patients are surviving without further relapses since the CNS episode. The median time to isolated CNS relapse was 457 days. Time to the initial CNS relapse was found to be the most important factor for predicting outcome. Thirty-five of the 55 patients with isolated relapse subsequently relapsed in the bone marrow, and of these, 32 have died. Twenty patients of the 100 with CNS disease as the first evidence of relapse developed two episodes of CNS involvement and 17 of these 20 patients subsequently relapsed in the bone marrow; only one patient survived. Twenty-five patients of the 100 have shown a pattern of chronic CNS disease with multiple CNS relapses. The overall disease-free survival for the 100 patients who developed one or more relapse was only 16%. These data demonstrate that the occurrence of a CNS relapse is an indicator of poor subsequent outcome. Comparison of results of groups receiving different CNS prophylaxis required careful consideration of the entire pattern of relapses and mortality.

Treatment of children with clear-cell sarcoma of the kidney: a report from the National Wilms' Tumor Study Group.

PURPOSE: To evaluate the effect of the sequential addition of doxorubicin (DOX) and cyclophosphamide (CTX) to the combination of vincristine (VCR) and dactinomycin (AMD) on the relapse-free survival of children with clear-cell sarcoma of the kidney (CCSK). PATIENTS AND METHODS: We determined the 6-year relapse-free survival rate for patients with CCSK treated on National Wilms' Tumor Study (NWTS)-1, NWTS-2, or NWTS-3 with the combination of VCR and AMD, with or without DOX, and for patients treated on NWTS-3 with the combination of VCR, AMD, and DOX with (regimen J) or without (regimen DD-RT) CTX. RESULTS: The 6-year relapse-free survival rate for the eight children with CCSK treated with VCR, AMD, and radiation therapy was 25.0%, compared with 63.5% for the 58 children treated with VCR, AMD, DOX, and radiation therapy (P = .09). The 6-year relapse-free survival rate for children with CCSK treated on regimen DD-RT was 64.6%, compared with 58.2% for those treated on regimen J (P = .79). CONCLUSION: We conclude that the addition of DOX to the combination of VCR plus AMD appeared to improve the 6-year relapse-free survival rate of children with CCSK. The addition of CTX in the dose and schedule used in NWTS-3 did not improve the 6-year relapse-free survival rate of children with CCSK. Because 30% of relapses occurred more than 2 years after diagnosis, prolonged follow-up evaluation of patients with CCSK is necessary.

Prognosis for Wilms' tumor patients with nonmetastatic disease at diagnosis--results of the second National Wilms' Tumor Study.

Multivariate statistical methods were used to study prognosis for 632 patients entered on the second National Wilms' Tumor Study who had nonmetastatic, unilateral disease at diagnosis. Separate analyses were conducted for each of four endpoints: abdominal recurrence, distant metastasis, relapse without regard to site, and death. The two most important predictors for metastasis and general relapse were an unfavorable (anaplastic or sarcomatous) histology and the presence of microscopically confirmed disease in the regional lymph nodes. Operative spillage of tumor increased the rates of abdominal recurrence and death, even after accounting for histology and lymph node effects. The presence of a tumor thrombus in the renal vein or IVC increased the risk of metastasis, and intrarenal vascular invasion was associated with general relapse after accounting for histology, lymph nodes, and spillage. However, these latter associations were weaker, and some uncertainty remains regarding the true prognostic import of such findings due to a high degree of collinearity among variables. By contrast to the results of a similar data analysis for the first National Wilms' Tumor Study, specimen weight had no bearing on outcome, and the effects of age at diagnosis were entirely explained by the association of age with other more critical factors.

Treatment of advanced neuroblastoma with supralethal chemotherapy, radiation, and allogeneic or autologous marrow reconstitution.

Ten children with recurrent metastatic (stage IV) neuroblastoma received local radiation therapy, supralethal chemotherapy, and total-body irradiation. Rescue with infusions of either allogeneic (four patients) or autologous (six patients) bone marrow followed. The drugs given to the first two patients were individualized combinations based on previous tumor responses. Both patients died with recurrent tumor three and nine months posttransplant. The eight remaining patients were treated more uniformly with local irradiation, VM-26, doxorubicin, melphalan (L-phenylalanine mustard), and 1,000-rad total-body irradiation in three fractions. Two of these patients had cardiac dysfunction and received no doxorubicin. Three children died in the immediate posttransplant period with disseminated fungal infections. A fourth relapsed and died nine months posttransplant. As of December 1, 1983, two children who received allogeneic marrow grafts have survived in complete remission for 54 and 36 months, and two children who received autologous marrow grafts have survived in complete remission for 35 and 22 months. These results suggest that relapsed metastatic neuroblastoma can be controlled by supralethal combinations of chemotherapy and irradiation coupled with bone-marrow rescue.

A comparison of four staging systems for localized and regional neuroblastoma: a report from the Childrens Cancer Study Group.

Four major staging systems have been used to estimate the prognosis for children with local and regional neuroblastoma (NBL). Data obtained at diagnosis for 251 neuroblastoma patients from two Childrens Cancer Study Group (CCSG) studies were analyzed according to staging systems of the CCSG, St Jude Children's Research Hospital, the Pediatric Oncology Group (POG), and the Union Internationale Contre le Cancer (UICC) tumor-nodes-metastasis (TNM) system. The most significant variables were found to be age, tumor stage, extent of tumor removal, transgression of the midline by tumor infiltration, and site of primary tumor. Involvement of lymph nodes per se was not a bad prognostic sign unless associated with extension beyond the midline, the latter being the single most important prognostic variable. All four staging systems had value for prognostication and all identified with accuracy the low stage patient (stage I, stage A) who fares well (greater than or equal to 87% survival). The CCSG definition of stages II and III disease discriminated prognostic groups best among the remaining patients, and was able to identify the child with local-regional NBL with poor survival. The estimated 5-year survival rates for children with regional tumor (stage III, IIIA[N]), according to the four systems were 44%, 74%, 74%, and 74% for the CCSG, St Jude, POG, and UICC methods, respectively. We conclude that all four staging systems effectively define good-prognosis patients with localized disease but that the CCSG staging system most accurately identifies patients with regional tumor who have a poor outcome.

Congestive heart failure after treatment for Wilms' tumor: a report from the National Wilms' Tumor Study group.

PURPOSE: We determined the frequency of and risk factors for congestive heart failure following treatment for Wilms' tumor that included doxorubicin. PATIENTS AND METHODS: Flow sheets and medical records were reviewed to identify cases of congestive heart failure in a cohort of patients treated on National Wilms' Tumor Studies (NWTS)-1, -2, -3, and -4. The frequency of congestive heart failure was estimated using the Kaplan-Meier method. A case-control study was conducted to determine the relationship among cumulative doxorubicin dose, site(s), total dose of abdominal and thoracic irradiation, sex, and the frequency of congestive heart failure. RESULTS: The cumulative frequency of congestive heart failure was 4.4% at 20 years after diagnosis among patients treated initially with doxorubicin and 17.4% at 20 years after diagnosis among those treated with doxorubicin for their first or subsequent relapse of Wilms' tumor. The relative risk (RR) of congestive heart failure was increased in females (RR = 4.5; P =.004) and by cumulative doxorubicin dose (RR = 3.3/100 mg/m(2); P <.001), lung irradiation (RR = 1.6/10 Gy; P =.037), and left abdominal irradiation (RR = 1.8/10 Gy; P =.013). CONCLUSION: We conclude that congestive heart failure is a risk of treatment with doxorubicin for Wilms' tumor. Additional follow-up of those children treated on NWTS-4 will be necessary to determine if the decrease in dose to 150 mg/m(2) significantly reduces this risk.

Effect of duration of treatment on treatment outcome and cost of treatment for Wilms' tumor: a report from the National Wilms' Tumor Study Group.

PURPOSE: National Wilms' Tumor Study (NWTS)-4 was designed to evaluate the efficacy, toxicity, and cost of the administration of different regimens for the treatment of Wilms' tumor (WT). PATIENTS AND METHODS: Between August 6, 1986 and September 1, 1994, 905 previously untreated children aged younger than 16 years with stage II favorable histology (FH) WT (low-risk [LR]), stages III to IV FH WT, or stages I to IV clear-cell sarcoma of the kidney (high-risk[HR]) were randomized after the completion of 6 months of chemotherapy to discontinue (short) or continue for 9 additional months (long) treatment with chemotherapy regimens that included vincristine and either divided-dose (standard [STD]) courses (5 days) or single-dose (pulse-intensive [PI]) treatment with dactinomycin. HR patients also received either divided-dose (STD) courses (3 days) or single-dose (PI) treatment with doxorubicin. RESULTS: The 4-year relapse-free survival (RFS) rates after the second randomization for LR patients were 83.7% for the 190 patients treated with short and 88.2% for the 187 patients treated with long chemotherapy (P = .11). The 4-year RFS rates after the second randomization for HR FH patients were 89.7% for the 256 patients treated with short and 88.8% for the 246 patients treated with long chemotherapy (P = .87). The charge for treatment with the short PI treatment regimens for all children with stages I through IV FH WT was approximately one half of that with the long STD treatment regimens. CONCLUSION: The short administration schedule for the treatment of children with WT is no less effective than the long administration schedule and can be administered at a substantially lower total treatment cost.